复合型石膏在净浆和自流平砂浆中的性能研究

研究了固氟脱酸处理后的氟石膏与α型半水石膏复合对净浆和自流平砂浆流动性、胶凝性能和力学性能的影响规律。结果表明:改性氟石膏与α型半水石膏的质量比为45∶55时,净浆的流动性能与力学性能最佳。随着改性氟石膏掺量增加,改性氟石膏早期水化速率较慢,24 h抗压强度出现下降趋势;随着龄期的延长,改性氟石膏进一步水化,晶体结构逐渐致密,7 d绝干抗压强度在38~50 MPa。石英砂掺量20%制备的复合型石膏基自流平砂浆的24 h抗折和抗压强度分别为3.2、12.1 MPa,30 min流动度损失为2 mm,符合JC/T 1023—2007《石膏基自流平砂浆》的要求。

Research on performance of composite gypsum on properties of paste and self-leveling mortar

In this article,the performance of modified fluorgypsum andα-hemihydrate gypsum on the fluidity,cementitious and mechanical properties of paste and self-leveling mortar was investigated.The results showed that when the ratio of modified fluorgypsum andα-hemihydrate gypsum was 45∶55,the mortar obtained the best flow and mechanical properties.The early stage hydration speed of anhydrite decreased with increase of the content of modified fluorgypsum and 24 h compressive strength was occurred on downward trend.With the increase of age,the modified fluorgypsum was further hydrated,the crystal structure of the hydrated paste was gradually consolidated and the 7 d absolutely dry compressive strength of the hydrated paste ranged from 38 to 50 MPa.24 h flexural strength and compressive strength of the composite of self-leveling mortar based on composite gypsum containing 20%of quartz sand could achieve 3.2 MPa and 12.1 MPa separately and its loss of fluidity after 30 min was 2 mm.Its performance could meet the relevant requirement of the standard JC/T 1023—2007"Gypsum-based self-leveling mortar".